A wide variety of commercial refrigerator display cabinets exist. One very common type of such a cabinet utilizes a series or array of hinged glass panel refrigerator doors. Glass panel refrigerator door arrays are widely used in a variety of commercial installations, such as those from which purchasers may select refrigerated or frozen food products or beverages.
Typical commercial refrigerator display cabinets, such as those used in supermarkets, include a cabinet frame which extends generally about the periphery of the front of the display cabinet. The frame includes a top or upper frame member, a bottom or lower frame member, and suitably laterally spaced side frame members extending vertically between the top and bottom frame members. The frame members are adapted to be arranged in a rectangular configuration with the respective end portions of the frame members forming 90 degree angles in each of the corners of the frame. Such frames also include one or more columns or mullions which extend vertically between the top frame member and the bottom frame member and are connected thereto. The mullions not only provide rigidification for the cabinet frame and structural support for the associated doors, but also define sealing surfaces against which portions of the door assemblies engage and seal for effective sealing of the refrigerated cabinet. The mullions may also be equipped with electrical conduits for delivering electrical power, such as to anti-condensation devices for the door assemblies. Mullions may also serve to mount fluorescent light fixtures.
The mullions in refrigerated cabinet door arrays are also frequently used to mount and house fluorescent light ballasts. Access to such ballasts is required from time to time for service and replacement. Conventional systems for mounting such ballasts on or internally of mullions make it difficult and time-consuming to gain access to the ballasts and to service and replace them.
Because time is of the essence in the service and replacement of ballasts, in part because such service and replacement occurs with a door to the cabinet open, in an environment in which the temperature should be kept at temperature of just above freezing in the case of a refrigerator, and well below freezing in the case of a freezer, the ballast mounting systems currently available and in use leave a great deal to be desired.
In many refrigerator and freezer cabinet frame assemblies, the doors in a series are all mounted on associated frames and mullions so that they may be opened from the same direction. As such, they are all similarly mounted, say on hinge pins on the left, with handles on the right. Thus, each mullion has a hinge axis at its front. To gain access to the interior of the mullion from the front requires removal of the door. Further, because of the use and location of anti-condensation heater wires in many cabinet arrays (the wires of which are usually positioned internally of the mullion at the front, both for access and so that they are located where they are most functional), front access to ballasts positioned internally of mullions require removal of the heater wires. This is also highly undesirable.
Mounting of the ballasts at the rear of the mullion also makes it very difficult to gain access for service and replacement. Considering that servicing of ballasts usually occurs while the refrigerator or freezer unit is in operation, and that the shelves in the freezer or refrigerator impede access to the rear of the mullion, it will be clear that shelving and possibly even doors must be removed when removing and securing ballasts which are mounted at the rear of mullions. Finally, fluorescent lights themselves are typically mounted on the rear surfaces of mullions. In such situations, if ballasts are to be removed from or through the rear of a mullion, the fluorescent fixtures must also be removed.
It would be desirable to provide refrigeration cabinet door and frame arrays having mullions from which ballasts can be quickly removed, and while the associated refrigerator or freezer remains in service.